The invention relates to an apparatus for temperature treatment of substrates, in particular, of semi-conductor crystal wafers, processed e.g. in the course of integrated circuit production.
As part of the process of integrated circuit fabrication, photolithographic procedures are applied to produce submicrometric structures on substrates such as mono crystalline silicon wafers. For that purpose, the substrate is cleaned and, if necessary, heated, so that the substrate surface is free of deposits. In addition, a surface treatment is performed to improve the adhesion of a photoresist coating which is applied to the substrates. When the substrates have been coated with photosensitive material known as photoresist, they are baked at a temperature of e.g. 85.degree. C. to evaporate the greatest portion of the photoresist solvent vehicle. After the exposure process and prior or subsequent to the development of the structures produced on the substrate, the photoresist layers undergo various temperature treatments.
Normally, temperature treatments of this type are performed by heating the substrates in a convection oven or by directing heat through inductive heating to the front or back surface of the substrate wafers. As an additional possibility for pre or postbaking substrate wafers layered with photosensitive material, the back of the crystal wafer can be thermally contacted. For these conduction heating, the semi-conductor crystal wafers coated with photoresist can be processed both individually or in cassettes either manually or automatically through the prebake process.